Hello,
This is a thread about the stacking technique for enhancing UFO videos, especially lights in the dark sky. I was asked about it by Internos and
Europa733.
There are many videos that have been deemed inconclusive, because lights in the sky can be many things, and there isn't enough information to rule
out many plausible explanations. This is a way to reveal hidden structures around these lights. I experimented recently with the video in the thread
Filmed 2 UFOS last night, here's the footage. The good news is even a completely
dark sky can be brightened and contrasted so the shape of the UFO becomes visible. This video was ideally suited for the stacking technique used by
amateur astronomers to increase resolution and make dark and fuzzy objects stand out clearly.
Dear ATSers, I need your help to:
1. locate UFO videos in original uncompressed format. Youtube and most video codecs filter out partly digital noise and lose most of the faint lights
that are nearly invisible to the naked eye. A few seconds of video are sufficient to do a stacking experiment, no need to upload 5 GB with audio as in
the previously mentioned thread.
I already had a look at:
-the uncompressed video from the "Triangle UFO *60 miles north of Bakersfield, CA" thread without success - the object is too dark.
-the "UFO VIDEO Elk Grove California Hologram" video - too small.
2. improve the quality of the resulting image. There are at least 4 processing steps:
1. alignment or stabilization
2. stacking
3. brightening/filtering
Alignment involves rotating/scaling or only positioning the frames. Stacking computes the mean color value of every pixel across frames, then a final
step is brightening / contrasting and optionally using noise filtering and sharpening filters. So far the best tool I found for 1. & 2. is
Registax. For 3. Photoshop of course.
A short list of how the "Filmed 2 UFOS last night, here's the footage" video was processed:
In VirtualDub-MPEG2 1.6.19 (VirtualDubMod has problems with the DV codec)
Choose a frame range that displays the UFO in focus, without too much hand shaking. For example 5933-6305.
File/Open video file (you may have to install codecs for Digital Video)
Video/Select Range (input first frame and number of frames)
Video/Filters (add deinterlace)
Streams/Stream list (disable sound, not needed)
File/Save as AVI
In Registax 4.0.1.0
Click button Select -> open deinterlaced uncompressed AVI
Method -> Multipoint, click lights on the left and right
Check Automatic processing
Click button Align
Optionally click button Histogram, move bars, click Stretch
Click button Save image, a 16 bit/channel TIFF is created
There was no filtering applied, except the default in Registax, whatever it is. As the noise is still very strong noise filtering only makes things
worse as far as I can see.
Final result:
I would have loved to see a weird shape, black triangle or saucer... maybe next time.
I am not an expert of this technique, only starting to look for the best tools and their parameters. Some people (video experts, astronomers) may have
information about the best way to use this one and other software for video stabilization. Registax is not suited for quick motion between frames.
With hand shake the objects often move too fast for Registax to be able to track them.
About stacking software I only know about Registax and Photoshop. I made a comparison with 200 frames and got the same result. Unfortunately the layer
alignment in Photoshop doesn't work at all when frames are mostly black.
edit: fixed links
[edit on 2008-11-17 by nablator]